Weft storage device for warp knitting machines

ABSTRACT

Weft thread storage device for a warp knitting machine having knitting needles for knitting weft and warp threads into a fabric web, includes a first and a second group of holding members spaced one from the other at respective locations at which they are adjacent opposite edges of a fabric web being knitted in the machine, and at least one support device disposed in the space between the groups of holding members and actuable to intercept weft threads extending between the groups of holding members and to transport them in direction toward the knitting needles of the machine.

[ Dec. 16, 1975 United States Patent [191 Frehn O AL/ .6 5

. 66/80 Hagel et Segum Bolles F 9223 6777 9999 HHHH 1307 76 67 t q 29 4 2404 3333 [73] Assignee; w s hl fh t & C0 Primary Examiner-Ronald Feldbaum Monchengladbach Germany Attorney, Agent, or Firm-Herbert L. Lerner Apr. 11, 1974 [57] ABSTRACT Weft thread storage device for a warp knitting ma- [22] Filed:

Appl. No.: 460,183

chine having knitting needles for knitting weft and warp threads into a fabric web, includes a first and a [30] Foreign Application Priority Data Apr. l3, 1973 GermanynmuwWWW-W 21318622 second group of holding members spaced one from the other at respective locatlons at which they are ad- [52] US. jacent pp edges of a fabric Web being knitted in the machine, and at least one support device disposed in the space between the groups of holding members and actuable to intercept weft threads extending between the groups of holding members and to transport 66/84 A 1m. D04B 23/06 [58] Field of Search 66/85 A, 84, 85; 156/439, 440

them in direction toward the knitting needles of the machine.

[56] References Cited UNITED STATES PATENTS 1,895,293 1/1933 66/84 A 8 Claims, 2 Drawing Figures U.S. Patent Dec. 16, 1975 Sheet 1 012 3,926,014

US. Patent Dec. 16, 1975 Sheet 2 of2 3,926,014

WEFT STORAGE DEVICE FOR WARP KNITTING MACHINES The invention relates to a weft thread storage device for warp knitting machines and, more particularly, to such a storage device having holding members which are located opposite one another adjacent respective opposing edges of the web of material and which transport the weft threads in direction toward the knitting tools.

The purpose of such weft thread storage devices is to receive continuously lengths of weft thread drawn out over the entire width of the knitted material, and to feed them to the knitting tools for interlinking or intermeshing with warp threads.

In the manufacture of very large widths of material or in the processing of very coarse weft yarns, it is essential to prevent the weft threads from sagging and to ensure that only the weft thread to be fed-in, in fact, uniformly over the full length thereof, will be gripped by the feeding means, such as a comb. Furthermore, care must be taken that this operation be carried out without error at the high feed velocities commonly employed today.

In order to attain thia objective, the weft threads were heretofore stretched as taut as possible from one holding member to the other, or rigid support slides were mounted below the groups of weft threads. The heavy stretching of weft threads causes an increased number of weft thread breaks, however, particularly when the threads have great lengths and the thread material is coarse and slightly twisted. Even when employing rigid support slides and reduced tension of the weft threads, inaccuracies in the spacing between one and the next weft threads in the transfer zone are so unavoidable that two weft threads can be fed-in simultaneously, for example, instead of a single weft thread.

It is accordingly an object of the invention to provide a weft storage device for warp knitting machine which avoids the aforedescribed shortcomings of the heretofore known weft storage devices of this general type.

With the foregoing and other objects in view, there is provided in accordance with the invention, a weft thread storage device for a warp knitting machine having knitting needles for knitting weft and warp threads into a fabric web, comprising a first and a second group of holding members spaced one from the other at respective locations at which they are adjacent opposite edges of a fabric web being knitted in the machine, and at least one support device disposed in the space between the groups of holding members and actuable to intercept weft threads extending between the groups of holding members and to transport them in direction toward the knitting needles of the machine.

In this manner, weft threads of very great length and with little tension also can be supported with minimal friction, while maintaining their predetermined mutual spacing up to their direct transfer to the knitting tools.

A simple but very effective support device is obtained in accordance with another particularly advantageous feature of the invention, wherein the support device comprises a helically wound flexible transport member having an appearance substantially similar to that of a cylindrical compression spring and having a multiplicity of windings between which the weft threads are receivable. Such a transport member can be produced relatively easily, for example, from a wear-resistant round piece of stock material, and the pitch of the individual turns can be adjusted to fit any thread pitch or distribution that may occur in the weft thread storage device.

According to a further feature of the invention, the groups of holding members are displaceable along a given transport path or trajectory, the flexible transport member having a longitudinal axis extending along a course corresponding to the transport path of the groups of holding members and over a predeterminable section thereof. If, for example, the holding members are disposed on circular discs, the transport member can be bent relatively easily into such circular shape and can extend, as viewed from the transfer point toward the knitting tools, over a given distance, such as a semicircle, for example. In this connection, the flexible transport member is, in a particularly advantageous manner, in accordance with the invention, supported rotatably or journalled at the ends thereof and driven or rotated in synchronism with the speed at which the groups of holding members are displaced along the given transport path.

It is possible to fabricate a flexible transport member according to the invention with such a high intrinsic stability as to permit the disposition of the transport member self-supportingly in bent condition and fixed at the ends thereof by bearings, underneath a group or bunch of weft threads. However, it is more advantageous to support the transport member at the inner radius thereof by a contact surface made of suitable material. In order to prevent lateral deflection of the flexible transport member in accordance with yet another feature of the invention, support discs are provided having guidance contours extending in correspondence with the course of the transport path or transport trajectory, the flexible transport member being disposed between the support discs.

The weft thread lengths which are picked up or caught by the holding members and continuously transported farther, are picked up or caught by the turns of the flexible transport member, further transported and transferred to the knitting tools, in a particularly advantageous manner when, in accordance with a further feature of the invention, the guidance contours of the support discs are of such shape as to gradually cover the spaces between or the pitch gaps defined by the helical windings of the flexible transport member.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as weft thread storage device for warp knitting machines, it is nevertheless not intended to be limited to the details shown, since various modifications may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The invention, however, together with additional objects and advantages thereof will be best understood from the following description when read in connection with the accompanying drawing, in which:

FIG. 1 is a perspective view of a weft thread storage device having a support device constructed in accordance with the invention of the instant application; and

FIG. 2 is a cross-sectional view of the support device of FIG. 1 in greater detail and in relation to the knitting tools of the warp knitting machine.

Referring now to the drawing and first particularly to FIG. 1 thereof, there is shown a support device 1 located intermediate two discs 2 and 3 of a circular weft thread storage device. The discs 2 and 3 of the weft storage device are provided with pin-shaped holding members 4 and spacer tabs 5 associated with these holding members 4. Weft threads 6 are slung around the holding members 4 continuously and in the form of loops. In the embodiment shown in FIG. 1, four weft threads 6 are simultaneously presented or fed to the weft thread storage device by a pneumatically driven thread laying device 8, which shuttles back and forth in a profiled tube 7. The discs 2 and 3 are secured to the shafts 9 and 10 and are both driven in synchronism with the knitting speed in direction of the arrow 11 toward the knitting tools 12 shown in FIG. 2.

In FIG. 2, the support device 1 is shown particularly clearly in detail. In the interest of clarity, the one disc 3 of the weft thread storage device, located in the extension behind the support device 1, together with the holding members 4 thereof, has been omitted from FIG. 2. The transport member 13, which twists or screws the weft threads 6 forward in direction of the arrow 11 synchronously with the transport velocity of the holding members 4 hereinbefore described with respect to FIG. 1, and accordingly also synchronously with the knitting speed, is constructed substantially in the form of a cylindrical compression spring. In the embodiment shown in FIG. 2, the distance from one weft thread 6 to an adjacent weft thread 6 is so great that every second turn 14 of the transport member 13 picks up or grasps one of these weft threads and ensures the pitch that is to be maintained. It is clearly seen in FIG. 2 that the spacing of the helical turns 14 can be accommodated to any desired pitch of the weft threads 6 either by changing the number of turns of the transport member 13 or by changing the spacing from turn to turn. At its front end, the flexible transport member 13 is provided with a bearing post 15 and is rotatably secured in a bearing plate 16. The rearward end of the transport member 13 is connected to a shaft 18, that is rotatably mounted or journaled in an arm or crossbar 17 and is supported at a collar 19 thereof in another arm or crossbar 20. The shaft 18 and, accordingly, the transport member 13 are set in rotation in direction of the arrow 23 through the bevel gears 21 and 22. To this end, the bevel gear 21 is secured to a shaft 24 which, in turn, revolves synchronously with the non-illustrated main drive shaft of a warp knitting machine. Below the transport member 13, there is provided a stationary support 25 preferably formed of plastic material suitable for slide bearings and having an outer contour 26 which establishes the radius of curvature of the arcuate longitudinal axis of the transport member 13. Of the support discs disposed for lateral guidance on both sides of the transport member 13, only one support disc 27 is shown in FIG. 2. From the shape of the guidance contour 28 thereof, the important additional function that the support discs 27 must fulfill besides lateral guidance of the transport member 13 is believed to be especially apparent. This additional function is the gradually occurring individual pickup or grasping of the weft threads 6 by the turns 14 and the transfer and positioning of each individual weft thread 6 into one of the pitch gaps 29 between the turns 14. When a weft thread 6 arrives at the end of the transport member 13 situated in the vicinity of the knitting tools 12, it is led by the respective holding members 4, which, as noted 4 hereinbefore, are not shown in FIG. 2, over the last turn 14 and seized by the comb 30, which feeds the weft thread 6 in a conventional manner to the knitting tools for interlinking or meshing with the warp threads.

Depending upon the width of the knitted web material and the corresponding length of the weft threads, as well as for especially heavyyarn, two or more support devices 1 can, of course, also be disposed between the discs 2 and 3 of a weft thread storage device according to the invention. Furthermore, transport member 13 can also move along a different arc which deviates from that of the illustrated embodiment.

I claim:

1. Weft thread storage device for a warp knitting machine having knitting needles for knitting weft and warp threads into a fabric web, comprising a pair of rotatable discs, a first and a second group of holding members each group mounted on one of said discs, said discs being spaced one from the other at respective locations at which they are adjacent opposite edges of a fabric web being knitted in the machine, and at least one intermediate support device disposed in the space between said groups of holding members to intercept weft threads extending between said groups of holding members, said discs and said intermediate support device being actuatable to transport said threads in direction toward the knitting needles of the machine, said support device having shape and dimensions similar to the discs.

2. Weft thread storage device according to claim 1 wherein said support device comprises a helically wound flexible transport member having an appearance substantially similar to that of a cylindrical compression spring and having a multiplicity of windings between which the weft threads are receivable.

3. Weft thread storage device according to claim 2 wherein said groups of holding members are displaceable along a given transport path, said flexible transport member having a longitudinal axis extending along a course corresponding to said transport path of said groups of holding members and over a predeterminable section thereof.

4. Weft thread storage device according to claim 3 wherein said flexible transport member is journaled at the ends thereof and is rotated in synchronism with the speed at which said groups of holding members are displaced along said given transport path.

5. Weft thread storage device according to claim 3 including support discs having guidance contours extending in correspondence with the course of said transport path, said flexible transport member being disposed between said support discs.

6. Weft thread storage device according to claim 5 wherein said guidance contours are of such shape as to gradually cover the spaces between the helical windings of said flexible transport member.

7. Weft thread storage device according to claim 1, wherein the intermediate support device has an annular slot and a flexible transport member comprising a cylindrical spring mounted in said slot.

8. Weft thread storage device according to claim 7, wherein the turns of the transport spring project from the annular slot of the intermediate support device to engage the weft threads. 

1. Weft thread storage device for a warp knitting machine having knitting needles for knitting weft and warp threads into a fabric web, comprising a pair of rotatable discs, a first and a second group of holding members each group mounted on one of said discs, said discs being spaced one from the other at respective locations at which they are adjacent opposite edges of a fabric web being knitted in the machine, and at least one intermediate support device disposed in the space between said groups of holding members to intercept weft threads extending between said groups of holding members, said discs and said intermediate support device being actuatable to transport said threads in direction toward the knitting needles of the machine, said support device having shape and dimensions similar to the discs.
 2. Weft thread storage device according to claim 1 wherein said support device comprises a helically wound flexible transport member having an appearance substantially similar to that of a cylindrical compression spring and having a multiplicity of windings between which the weft threads are receivable.
 3. Weft thread storage device according to claim 2 wherein said groups of holding members are displaceable along a given transport path, said flexible transport member having a longitudinal axis extending along a course corresponding to said transport path of said groups of holding members and over a predeterminable section thereof.
 4. Weft thread storage device according to claim 3 wherein said flexible transport member is journaled at the ends thereof and is rotated in synchronism with the speed at which said groups of holding members are displaced along said given transport path.
 5. Weft thread storage device according to claim 3 including support discs having guidance contours extending in correspondence with the course of said transport path, said flexible transport member being disposed between said support discs.
 6. Weft thread storage device according to claim 5 wherein said guidance contours are of such shape as to gradually cover the spaces between the helical windings of said flexible transport member.
 7. Weft thread storage device according to claim 1, wherein the intermediate support device has an annular slot and a flexible transport member comprising a cylindrical spring mounted in said slot.
 8. Weft thread storage device according to claim 7, wherein the turns of the transport spring project from the annular slot of the intermediate support device to engage the weft threads. 